A standard such apparatus normally has a rigid frame having a front end to one side of the workpiece to be embossed and a rear end to the other side thereof. An anvil on the front frame end is engageable with the one side of the workpiece and a tool is supported on the rear end of the frame for longitudinal movement relative to the workpiece. The tool is basically a punch of very hard metal that is pressed with sufficient force against the workpiece, which itself is braced against the anvil, that the workpiece plastifies and flows where engaged by the tool. The face of the tool bears raised indicia that are thus imprinted into the workpiece surface and that, for instance, identify the manufacturer.
In a standard such apparatus, as described in German Pat. No. 2,340,528 of E. Kruse, the tool is held in a chuck and can only be exchanged for a different one when the system is down. Thus it is necessary to provide all the necessary information on a single tool, which must be changed each time the run of a particular workpiece is complete.